The invention pertains to the processes and materials used to reduce the reflection of electromagnetic waves off a wall of a structure or infrastructure.
It is more specifically designed for a process to fasten an intrinsic element absorbing electromagnetic waves onto a wall of a structure, moving or not, or an infrastructure.
There are known methods used to reduce the electromagnetic wave reflectivity of a structure or infrastructure and thereby reduce their radar signature. These methods are essentially and principally comprised of camouflage covers, such as nets covering the structure or infrastructure. Thus, a net made of material that absorbs electromagnetic waves is used, and this net is attached to the structure, for example, with fastening straps or cables. Such a method can be quite cumbersome to use, particularly for structures or infrastructures containing moving parts.
Other methods proposed were the use of rigid panels including a synthetic resin as the matrix with an imbedded element that absorbs electromagnetic waves. However, although perfectly suited to make infrastructures or to protect flat surfaces and simple shapes, these panels are very difficult to use for the protection of moving structures, or non-flat surfaces or complex shapes. Moreover, any damage to part of the panel is very difficult to repair and most often requires the replacement of the entire panel.
To correct these drawbacks, the invention proposes a process to fasten an intrinsic element absorbing electromagnetic waves such as a net, for example, onto a wall of a structure or infrastructure which will enable it to be attached simply and reliably to any surface of any shape, even by unspecialized persons, and to easily repair damaged parts with a simple sealing or filling of these parts.
Accordingly, the invention is designed for a process to fasten an intrinsic element absorbing electromagnetic waves onto a wall of a structure or infrastructure, characterized as follows in that it consists of:
applying a coating onto a surface of the aforesaid wall by means of a syntactic foam that is transparent to electromagnetic waves and that has the rheological properties of a mastic; PA0 placing the aforesaid intrinsic absorbent element into or onto the aforesaid syntactic foam coating; PA0 letting the aforesaid syntactic foam harden.
Of course, for the coating to adhere to the wall, it is usually necessary to clean the surface of the wall, namely by degreasing or sand blasting, for example; these operations are those that are normally conducted to prepare a surface prior to applying a coat of paint or applying any type of coating.
The syntactic foam is a composite material including as its matrix, a resin such as an epoxy resin, polyester, phenolic, silicone, for example, and a volume-reduction filler consisting of hollow or porous microspheres, such as, for example, microscopic particles of glass, plastic, zeolite, vermiculite, and having a low density.